The episode had 4.63 million viewers on average, when precise timings are taken into account - another significant rise on last episode, and the highest overnight rating so far this series, topping the series opener's overnight figure of 4.58 million.
Doctor Who was the second most viewed programme of the day, behind Strictly Come Dancing. It beat its direct competition, which was a Rugby World Cup game between New Zealand and France.
The consolidated viewing figures will be released next week, where Doctor Who should rise considerably.
[Source: Gallifrey Base]